母源蛋白Trim32在囊胚形成中的作用与机制研究

TRIM32是我们前期筛选到的卵细胞特异高表达、人鼠间高度保守的母源蛋白，在早期胚胎发育中尚无功能研究。其高表达于小鼠卵细胞和受精卵，2-细胞阶段开始表达量下降直至囊胚阶段；受精卵中过表达TRIM32可致囊胚形成率下降；其是一个E3泛素连接酶，以泛素化蛋白芯片筛选结合软件分析初步发现LAMA1可能是其候选底物；已发现LAMA1特异性表达于囊胚滋养外胚层细胞中，参与囊胚腔的形成；通过受精卵中过表达TRIM32发现囊胚中LAMA1表达量降低，提示TRIM32可能通过调节LAMA1泛素化降解参与囊胚形成过程。本研究拟运用过表达、沉默策略研究TRIM32在囊胚形成中的作用，并通过泛素化实验和挽救实验全面深入探讨TRIM32介导LAMA1蛋白泛素化降解，参与小鼠囊胚形成的作用机制。研究成果将有助于改善体外培养囊胚率、提高IVF成功率。

TRIM32 protein was a poorly studied maternal protein in the early embryonic development and highly homologous to the mouse, which was screened from the mouse oocyte protein expression profile in the laboratory. It is a proven E3 ubiquitin ligase, the mRNA kept specificity and overexpression in the oocytes and fertilized eggs and the expression level decreased significantly after cleavage and maintained a low level at the following stages. Preliminary studies showed that the overexpression of TRIM32 protein induced the decrease of blastocyst formation rate. LAMA1 protein was found as the substrate protein by using the ubiquitin protein chip and the expression of LAMA1 decreased after the overexpression of TRIM32 in the fertilized eggs. LAMA1 kept specificity expression in the parietal endoderm and participate in the formation of blastocyst. By using siRNA microinjection, in vitro transcription, and embryo transplant technology, we intend to prove that the TRIM32 could mediate LAMA1 protein the ubiquitin chain formation and degradation and play an important role in the mouse blastocyst formation. Research will clarify the function and mechanism of the trim32 protein, which is helpful to improve the rate of blastocyst formation and the success rate of IVF.